Cathode active material for lithium secondary battery and lithium secondary battery having the same

Abstract

Provided are a cathode active material for a lithium secondary battery and a lithium secondary battery including the same. The cathode active material includes a lithium composite oxide represented by the following Chemical Formula 1. Li[Li z A]O 2 A={M 1 1-x-y (M 1 0.78 Mn 0.22 ) x }M 2 y   [Chemical Formula 1] In Chemical Formula, M 1 and M 2 are independently one or more selected from a transition element, a rare earth element, or a combination thereof, M 1 and M 2 are elements that are different from each other, −0.05≦z≦0.1, 0.8≦x+y≦1.8, and 0.05≦y≦0.35, and Ni has an oxidation number of 2.01 to 2.4.

1 . A cathode active material for a lithium secondary battery, comprising a lithium composite oxide represented by the following Chemical Formula 1:
   Li[Li z A]O 2        A={M 1   1-x-y (M 1   0.78 Mn 0.22 ) x }M 2   y   [Chemical Formula 1]
   wherein, M 1  and M 2  are independently one or more selected from a transition element, a rare earth element, or a combination thereof, and M 1  and M 2  are elements that are different from each other, and −0.05≦z≦0.1, 0.8≦x+y≦1.8, 0.05≦y≦0.35, and Ni has an oxidation number of 2.01 to 2.4.   
     
     
         2 . The cathode active material of  claim 1 , wherein the z, x, and y are in the following ranges of −0.03≦z≦0.09, 1.0≦x+y≦1.8, and 0.05≦y≦0.35. 
     
     
         3 . The cathode active material of  claim 1 , wherein M 1  is selected from the group consisting of Ni, Co, Ti, Mg, Cu, Zn, Fe, Al, La, Ce, and a combination thereof, and
 M 2  is selected from the group consisting of Ni, Co, Ti, Mg, Cu, Zn, Fe, Al, La, Ce, and a combination thereof.   
     
     
         4 . The cathode active material of  claim 2 , wherein M 1  is Ni and M 2  is Co. 
     
     
         5 . The cathode active material of  claim 1 , wherein the lithium composite oxide is a secondary particle assembled by primary particles, and the secondary particle is spherical. 
     
     
         6 . The cathode active material of  claim 5 , wherein the primary particle has an average long particle diameter ranging from 50 nm to 2.5 μm. 
     
     
         7 . The cathode active material of  claim 6 , wherein the primary particle has an average long particle diameter ranging from 200 nm to 2.3 μm. 
     
     
         8 . A lithium secondary battery comprising:
 a cathode comprising a lithium composite oxide represented by the following Chemical Formula 1 cathode active material;   an anode comprising an anode active material; and   an electrolyte:
   Li[Li z A]O 2    
   A={M 1   1-x-y (M 1   0.78 Mn 0.22 ) x }M 2   y   [Chemical Formula 1]
 
   wherein, M 1  and M 2  are independently one or more selected from a transition element, a rare earth element, or a combination thereof, M1 and M2 are elements that are different from each other, −0.05≦z≦0.1, 0.8≦x+y≦1.8, and 0.05≦y≦0.35, and Ni has an oxidation number of 2.01 to 2.4, −0.05≦z≦0.1, 0.8≦x+y≦1.8, 0.05≦y≦0.35, and Ni has an oxidation number of 2.01 to 2.4.   
     
     
         9 . The lithium secondary battery of  claim 8 , wherein the z, x, and y are in the following ranges of −0.03≦z≦0.09, 1.0≦x+y≦1.8, and 0.05≦y≦0.35. 
     
     
         10 . The lithium secondary battery of  claim 8 , wherein M 1  is selected from the group consisting of Ni, Co, Ti, Mg, Cu, Zn, Fe, Al, La, Ce, and a combination thereof, and
 M 2  is selected from the group consisting of Ni, Co, Ti, Mg, Cu, Zn, Fe, Al, La, Ce, and a combination thereof.   
     
     
         11 . The lithium secondary battery of  claim 8 , wherein M 1  is Ni and M 2  is Co. 
     
     
         12 . The lithium secondary battery of  claim 8 , wherein the lithium composite oxide is a secondary particle assembled by primary particles and is spherical. 
     
     
         13 . The lithium secondary battery of  claim 8 , wherein the primary particle has an average long particle diameter ranging from 50 nm to 2.5 μm. 
     
     
         14 . The lithium secondary battery of  claim 13 , wherein the primary particle has an average long particle diameter ranging from 200 nm to 2.3 μm.